So this light really gets you respect. I call it the commuter cuz it really doesn't put light down on the ground like the other light. ..But the visibality is great. Perfect for in the city when you need to be seen. A car driver sees you coming and they can't figure out if your a motorcycle or scooter..or a car with a headlight out.. even a train (sez my friend)and it (the light) can be made for under 5 bucks at Home Cheapo. The battery pack is still gonna run you a bit 20 to 30 bucks(use the same battery pack as last light) 10 AA Ni-MH at 1.2 volts thats 12 volts 2500 mAh in the cute little plastic holder from Radio shack or some other electronic place.
This light is 11 watts so on this battery pack it should run just under 3 hours. I did a late night city ride last Friday night and it held strong for the 2 1/2 hours we rode.
Another of my bike lights
http://www.instructables.com/ex/i/9129E65EFFBE102880EC001143E7E506/edit.jsp
Congrats a nice simple project quite well executed & documented.
I live in Australia so no "Home Depots" as with many other countries I suppose.
So can you say exactly what a "Malibu ML11P2 sealed beam" is. I guess it's a sealed halogen luminary, off maybe some small vehicle, motorbike maybe??
Can you please provide some more detail so we can seek out alternatives, size, originally used for .......... etc.
Also the suggestion to use a regulator seems sound, only about 1.0 amp draw for 12 V/11watts, this could be home brewed & put in the battery pack. What do you think. Downside I see is that even a sealed lead/acid battery quickly drops from 13.8 to about 12V so you might ever only be able to access say 60% of available charge.
Was your "ride test with the NIMH 10 cell setup you recommend?
Thanks
Peter O
http://www.google.com/products/catalog?q=12+volt+battery&um=1&hl=en&biw=1436&bih=807&ie=UTF-8&cid=2415590567703803192&ei=Ce40TYu2LMGs8AaB3vTwCA&sa=X&oi=product_catalog_result&ct=result&resnum=3&ved=0CH8Q8wIwAg#
(or the giantass ones in the hardware store)
it would give you better "bang for the buck" and it would be easier to make :-)
or maybe a batterypack from a cordless powertool.
If you want to check out the type of LEDs that really put light out http://www.luxeon.com/index.html
I ordered some 1 and 3 watt emitters to the electronic dumbby they were imposible to use. I burn them all out hooking them straight to batteries or I couldnt get any light out of them under voltaged... Look at that web site those are "The" LEDs
http://www.theledlight.com/dcbulbs.html